Saw-jointer



F, M. BOULT. SAW JOINTER.

APPLICATION FILED JULY 25, l9l8.

Patented June 17, 1919.

II/VEA/TOR F: M Boulifi By ATTORNEYS fii FRANK MURRAY BOULT, 0F OSTERVILLE, MASSACHUSETTS.

SAW-JOINTER.

To all whom it may concern:

Be it known that I, FRANK M. Boom, a citizen of the United States, and a resident of Osterville, in the county of Barnsta'ble and State of Massachusetts, have invented a new and Improved Saw-Jointer, of which the following is a full, clear, and eXact description. I

This invention relates to saw jointers or tools for dressing down the pointsof saw teeth so as to make said teeth all of the same length or depth.

Among the objects of the present invention, therefore, is to provide a jointer comprising a file holding implement having a number of important structural advantages over the many other types of jointers on the market and with which I am familiar. To this end I provide a yoke shaped bracket constituting the main portion of the implement, said bracket comprising a plurality of depending legs for operation on opposite sides of the saw being jointed, said legs furthermore being provided with a plurality of shoulders lying substantially in a horizontal plane and against which the active face of a file'is adapted to be clamped. This plane, therefore, coincides with the plane determined by the points of the saw teeth that are being reduced in length.

A further important object of this improvement is to provide a means whereby the jointer automatically accommodates itself to different thicknesses or gages of saw blades.

the invention is to im- Another object of holding the file in rehaprove the means for ble position.

With he foregoing and other objects in view the invention consists in the arrangement and combination of parts hereinafter described and claimed, and while the invention is not restricted to the exact details of construction disclosed or suggested herein, still for the purpose of illustrating a practical embodiment thereof reference is had to the accompanying drawings, in which like reference characters designate the same parts in the several views, and in which- V Figure 1 is a side elevation of my improvement with a common form of three cornered file clamped therein.

Fig. 2 is a plan view of the same; and

Fig. 3 is a vertical transverse section on the line 3-3 of Fig. 1.

Specification of Letters Patent.

Patented June 17, 1919.

Application filed July 25, 1918. Serial No. 246,755.

Referring now more specifically to the drawings the invention comprises a bracket having an arched crown 10 with which are formed and from which depend a series of three rigid legs 11, 12 and 13. The legs 11 and 12 depend on the same side of the saw, represented at 'S, Fig. 3, while the remaining leg 13 depends on the opposite side of the saw. Considered in connection with the transverse dimension the leg 13 is located between the planes of the first two legs.

Each of the legs 11 and 12 is provided with an offset forming a shoulder 14 and the leg 13 is provided with a corresponding inwardly projecting shoulder 15, all of these shoulders having upper horizontal faces lying in the same plane. The inner faces of the legs 11 and 12 below the shoulders 14: are fiat and substantially vertical in practice, since they are adapted to bear against one face of the saw. These faces, however, are beveled off slightly at 16 adjacent to the shoulders to provide a clearance for the saw teeth 8. The open space above the plane of the shoulders 14: and 15 and below the crown 10 serves to accommodate a file, the one indicated at 17 being of the common three cornered type one face of which is adapted to coincide with the plane aforesaid or bear against the upper faces of said shoulders. Located also mainly within the space just referred to is a movable jaw or follower 18 having a longitudinal central groove 18 in its lower face into which the upper edge or apex of the file is seated. This follower is of relatively great length providing a firm and substantial grip upon the file when subjected to pressure by means of the set screw 19 which is tapped down through the center of the crown and bears against the center of the top surface of the follower. The follower is held positively from endwise movement with respect to the yoke by means of laterally projecting lugs 20 which bear against the edges of the legs 11 and 12. With respect to the file I would call attention to the fact that whereas files of this type are usually worn out first along their corners, especially in the filing of saws, the device set forth herein is designed in such a manner that files that are otherwise practically useless may be employed to advantage inasmuch as the longitudinal centers of the flat faces of the file are the parts that are used for jointing and hence while the file may be useless for the usual purposes it may be used to good advantage for ointing.

For a tool of this type to be of greatest utility and yet be easy to apply to the work it is essential that no adjustment be re-- quired either for applying the jointer to the saw teeth or for adapting it to various thicknesses of saw blades. To this end, therefore, I provide an automatic adapter in the nature of a plunger 21 consisting of a smooth bolt having a rounded head 22 held resiliently against the face of the saw opposite the legs 11 andlz, by means of a coil spring 23 surrounding the bolt and located between the head thereof and the leg 13. This bolt is held from accidental separation from the leg 18 by means of a cotter pin 24, or its equivalent. The rounding of the head 22 facilitates the admission of the saw into its place adjacent to the file, and moreover this form of the head is most favorable for the reciprocations that are given to the tool in practice. Note especially in Fig. 3 the plunger or bolt 21 is so located with re spect to the plane of the file as to operate against the face of the saw as near as possible to the teeth and yet without being brought into contact with the cutting edges of the teeth. For this reason, therefore, I prefer to so incline the axis of the bolt as to cause the upper portion of the rounded head 22 to bear especially against the face of the saw. In other words, the upper portion or edge of the rounded head will thus be brought into contact with the saw closer to the teeth than any other portion of the head if the axis of the bolt were otherwise disposed. I find moreover that there is a a tendency for the friction between the saw Copies of this patent may be obtained for five cents each, by addressing the Commissioner and the bolt head to cause a rotation or rolling action of the adapter in its bearing in the lower end of the leg 13, therefore, with the contact between the bolt head and the saw made effective only at the upper edge of the rounded head the friction between the tool and the faces of the saw may be materially reduced due to the rotation of the bolt around its axis, and yet the spring may he sufliciently strong to maintain the tool in definite position with respect to the faces of the saw. In other words the peculiar construction and action of the automatic adapter are such that there is a minimum tendency of lateral rolling or rocking action ofthe implement in practice which would tend otherwise to cause rounding of the points of the teeth or to make one series of teeth shorter than the other.

I claim:

In a saw jointer, the combination of a yoke comprising a crown and a series of three legs formed integral therewith, two of the legs depending on one side of the saw while the third leg depends on the opposite side of the saw therefrom, all three of the legs being provided with flat topped shoulders on their inner faces, a file within the yoke, and means to detachably lock the file firmly in place therein with its active face against said shoulders, said locking means including a longitudinally extending follower having in its lower face a longitudinal central groove into which the apex of the file is projected whereby the center of the active face of the file will be caused to cooperate with the saw teeth irrespective of the size of the file.

FRANK MURRAY BOULT.

of Patents,

Washington, D. G. 

